The present invention relates to the use of galvanically deposited aluminum layers for contacts of microcircuits.
The use of galvanically deposited aluminum layers produced of nonaqueous solutions under protection gas, for protection against corrosion has been known, for example from EP-PS No. 0,042,504.
Semiconductor structural components utilized in microelectronics are normally electrically connected to the base circuit by ultra-violet welding. Wire connections with which a suitable tool (key or capillary tube) welds the wire, with the aid of the ultraviolet radiation or the ultraviolet radiation and heat, to contact spots of the semiconductor-and-substrate circuit, and superposing contact methods with which the contact tabs of the intermediate carrier or support are welded with the aid of a suitable tool to the semiconductor and further to the base circuit are different.
For metallurgical and coatings-producing grounds an aluminum layer deposited on the side of the semiconductor penetrates its surface. Gold layers produced by metallizing, which are vaporized, are galvanically deposited or compressed as a paste. In addition, all the circuits nowadays are provided with contacts of aluminum or gold wire. This always leads to a material pair aluminum-gold either on the semiconductor with connections with gold wire or on the base circuit with connections with aluminum wire. This material pairs can, however, cause, due to the formation of intermetallic compounds a so-called purple plague or, due to a contact corrosion, a reduced reliability of the whole circuit.